LiFePO4 battery pack capacity estimation for electric vehicles based on charging cell voltage curve transformation

► The uniform charging cell voltage curves (CCVC) hypothesis is proposed. ► Cell capacities can be estimated by overlapping CCVCs using CCVC transformation. ► A simplified approach using voltage-capacity rate curve (VCRC) is proposed. ► Genetic Algorithm (GA) is implemented to find the optimum transformation parameter. ► The battery pack capacity can be precisely estimated with the proposed method.